Waste of time and money. Unless the amplifier was designed incorrectly in the first place and is not meeting the requirements of the op-amp; it is unlikely that the performance would increase.

If you are going to:
-Measure the before and after performance with test equipment.
-Modify the amplifier to the requirements of the new op-amp.
-Use a proper audio op-amp and not one designed for something else.

Then you may be able to net a performance increase but at that point you had might as well just design your own amplifier.

If it sounds different after you changed the op-amp it will be because:
A)The amplifier incompatible with the original op-amp
B)The new op-amp is more compatible than the old op-amp
C)You think it sounds different when it really doesn't (NOTE: the above two are more likely in this circumstance).

Waste of time and money. Unless the amplifier was designed incorrectly in the first place and is not meeting the requirements of the op-amp; it is unlikely that the performance would increase.

If you are going to:
-Measure the before and after performance with test equipment.
-Modify the amplifier to the requirements of the new op-amp.
-Use a proper audio op-amp and not one designed for something else.

Then you may be able to net a performance increase but at that point you had might as well just design your own amplifier.

If it sounds different after you changed the op-amp it will be because:
A)The amplifier incompatible with the original op-amp
B)The new op-amp is more compatible than the old op-amp
C)You think it sounds different when it really doesn't (NOTE: the above two are more likely in this circumstance).

So again, waste of time and money.

I know you are just towing the party line, but this is rather incomplete and one line didnt fit your conclusion, but you simply ignored that and made it fit.

Quote:

B)The new op-amp is more compatible than the old op-amp

which can relate to fitting the amp, or the headphone load better, how pray tell would that be a waste of time and money? sorry but this is most certainly not a perfect model of a world we live in, design mistakes, as well as unexpected load interactions can and do happen. your model for reality is flawed (oversimplified) and thus useless

a simple CMOY is never going to meet your expected model, but youre correct, while you may make some changes by choosing a better opamp for it, it would be better to just choose a properly designed amp and build it

the TLE2072 is nothing more then a slightly quieter tl072 they sound the same they can be pleasing in the right circuit but nothing amazing

Not so

There are many differences. The TLE2072 has a -/+ 80ma output capability (per opamp in the dual package) which puts it way ahead of the competition.
Slew rate of around 35V/us, a wider operating voltage range.......